The item is a flight safety critical aircraft part (fscap).
A nut having 6 flat sides and an integral washer which extends beyond the flats or periphery. An integral feature is incorporated for locking on the threads of a mating member.
Classification: Nuts of iron or steel
NSN 5998-01-335-3253
NSN 4140-01-042-1347
NSN 6220-00-094-2919
NSN 2925-00-394-2332
NSN 5998-01-383-4973
NSN 6105-01-318-7669
NSN 6130-01-621-4910
NSN 6220-01-056-5169
NSN 5920-00-519-6830
NSN 5996-01-578-6955
NSN 6645-00-163-9580
NSN 5975-01-313-6943